Wordpress - Custom Post Type Next/Previous Link?

<?php
$prev_post = get_previous_post();
if($prev_post) {
   $prev_title = strip_tags(str_replace('"', '', $prev_post->post_title));
   echo "\t" . '<a rel="prev" href="' . get_permalink($prev_post->ID) . '" title="' . $prev_title. '" class=" ">&laquo; Previous post<br /><strong>&quot;'. $prev_title . '&quot;</strong></a>' . "\n";
}

$next_post = get_next_post();
if($next_post) {
   $next_title = strip_tags(str_replace('"', '', $next_post->post_title));
   echo "\t" . '<a rel="next" href="' . get_permalink($next_post->ID) . '" title="' . $next_title. '" class=" ">Next post &raquo;<br /><strong>&quot;'. $next_title . '&quot;</strong></a>' . "\n";
}
?>

If you need next/previous links for single posts, there is the built in next_post_link function and matching previous_post_link, both of which should probably be used within the loop.

For archives, use next_posts_link and previous_posts_link.

All of these will work fine with custom post types.